function SuperType () {
    this.name = ['zhangsan','lisi']
}
function SubType () {
    SuperType.call(this)
}
/*
在SubType构造函数中,通过调用父构造函数的call方法实现继承,
于是SubType的每个实例都会将SuperType构造函数中属性复制一份
*/ 
// 
var instance1 = new SubType()
instance1.name.push('marry')
console.log(instance1.name);
/*
0: "zhangsan"
1: "lisi"
2: "marry"
*/
var instance2 = new SubType()
instance2.name.push('marry2')
console.log(instance2.name);
/*
0: "zhangsan"
1: "lisi"
2: "marry2"
*/
/*
   缺点:
        只能继承父类的属性和方法,不能继承原型属性和方法;
        无法实现复用,每个子类都有父类实例函数的副本,影响性能
*/
